Diffuse

Antiphospholipid Antibody Syndrome

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Antiphospholipid Antibody Syndrome, Antiphospholipid Syndrome, Lupus Anticoagulant Disorder

  • See Also
  1. Systemic Lupus Erythematosus
  • Pathophysiology
  1. Antiphospholipid Antibodies bind cell membrane phospholipids (including vascular endothelium)
    1. Antibody binding triggers inflammatory and prothrombotic changes
  2. Increases risk of recurrent thrombosis of any size vessel
  3. May have no link with Systemic Lupus Erythematosus despite early associations
  • Diagnosis
  1. Major clinical associations
    1. Venous thrombosis
      1. Deep Vein Thrombosis
      2. Pulmonary Embolism
    2. Arterial thrombosis
      1. Cerebrovascular Accident (CVA)
      2. Transient Ischemic Attacks
      3. Myocardial Infarction
      4. Gangrene
    3. Recurrent Pregnancy Loss
    4. Thrombocytopenia
    5. Hemolytic Anemia
  2. Other clinical associations
    1. Heart Valve abnormality
    2. Positive Coombs tests
    3. Livedo Reticularis
    4. Migraine Headaches
    5. Leg ulcers
    6. Myelopathy
    7. Chorea
    8. Pulmonary Hypertension
    9. Avascular necrosis
  • Labs
  1. Partial Thromboplastin Time (PTT) prolonged
  2. Autoantibodies are present in 5% of healthy patients
  3. Positive Anticardiolipin Antibody (most sensitive test)
    1. IgG > 20 GPL
    2. IgM > 20 MPL units
    3. Possibly IgA positive
  4. Positive Lupus Anticoagulant (most specific test)
  5. Anti-B2-Glycoprotein I Autoantibodies
  6. False Positive VDRL (30-40%)
  • Prevention of thrombotic complications
  1. Anticoagulation
    1. Coumadin
      1. Moderate to high dose (INR >2) is protective
      2. Low dose (INR <1.9) does not prevent thrombosis
    2. Aspirin
      1. Protects against pregnancy loss
      2. Does not protect against thrombosis
  2. Avoid factors predisposing to thrombosis
    1. Oral Contraceptive use
    2. Immobility
  3. Modify atherosclerotic risk factors
    1. Hyperlipidemia
    2. Tobacco Abuse
    3. Diabetes Mellitus
  • References
  1. Levine (2002) N Engl J Med 346:752-63 [PubMed]